xref: /dragonfly/sys/dev/drm/i915/intel_panel.c (revision 0fe46dc6)
1 /*
2  * Copyright © 2006-2010 Intel Corporation
3  * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22  * DEALINGS IN THE SOFTWARE.
23  *
24  * Authors:
25  *	Eric Anholt <eric@anholt.net>
26  *      Dave Airlie <airlied@linux.ie>
27  *      Jesse Barnes <jesse.barnes@intel.com>
28  *      Chris Wilson <chris@chris-wilson.co.uk>
29  */
30 
31 #include <linux/kernel.h>
32 #include <linux/moduleparam.h>
33 #include <linux/pwm.h>
34 #include "intel_drv.h"
35 
36 #define CRC_PMIC_PWM_PERIOD_NS	21333
37 
38 void
39 intel_fixed_panel_mode(const struct drm_display_mode *fixed_mode,
40 		       struct drm_display_mode *adjusted_mode)
41 {
42 	drm_mode_copy(adjusted_mode, fixed_mode);
43 
44 	drm_mode_set_crtcinfo(adjusted_mode, 0);
45 }
46 
47 /**
48  * intel_find_panel_downclock - find the reduced downclock for LVDS in EDID
49  * @dev: drm device
50  * @fixed_mode : panel native mode
51  * @connector: LVDS/eDP connector
52  *
53  * Return downclock_avail
54  * Find the reduced downclock for LVDS/eDP in EDID.
55  */
56 struct drm_display_mode *
57 intel_find_panel_downclock(struct drm_device *dev,
58 			struct drm_display_mode *fixed_mode,
59 			struct drm_connector *connector)
60 {
61 	struct drm_display_mode *scan, *tmp_mode;
62 	int temp_downclock;
63 
64 	temp_downclock = fixed_mode->clock;
65 	tmp_mode = NULL;
66 
67 	list_for_each_entry(scan, &connector->probed_modes, head) {
68 		/*
69 		 * If one mode has the same resolution with the fixed_panel
70 		 * mode while they have the different refresh rate, it means
71 		 * that the reduced downclock is found. In such
72 		 * case we can set the different FPx0/1 to dynamically select
73 		 * between low and high frequency.
74 		 */
75 		if (scan->hdisplay == fixed_mode->hdisplay &&
76 		    scan->hsync_start == fixed_mode->hsync_start &&
77 		    scan->hsync_end == fixed_mode->hsync_end &&
78 		    scan->htotal == fixed_mode->htotal &&
79 		    scan->vdisplay == fixed_mode->vdisplay &&
80 		    scan->vsync_start == fixed_mode->vsync_start &&
81 		    scan->vsync_end == fixed_mode->vsync_end &&
82 		    scan->vtotal == fixed_mode->vtotal) {
83 			if (scan->clock < temp_downclock) {
84 				/*
85 				 * The downclock is already found. But we
86 				 * expect to find the lower downclock.
87 				 */
88 				temp_downclock = scan->clock;
89 				tmp_mode = scan;
90 			}
91 		}
92 	}
93 
94 	if (temp_downclock < fixed_mode->clock)
95 		return drm_mode_duplicate(dev, tmp_mode);
96 	else
97 		return NULL;
98 }
99 
100 /* adjusted_mode has been preset to be the panel's fixed mode */
101 void
102 intel_pch_panel_fitting(struct intel_crtc *intel_crtc,
103 			struct intel_crtc_state *pipe_config,
104 			int fitting_mode)
105 {
106 	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
107 	int x = 0, y = 0, width = 0, height = 0;
108 
109 	/* Native modes don't need fitting */
110 	if (adjusted_mode->crtc_hdisplay == pipe_config->pipe_src_w &&
111 	    adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h)
112 		goto done;
113 
114 	switch (fitting_mode) {
115 	case DRM_MODE_SCALE_CENTER:
116 		width = pipe_config->pipe_src_w;
117 		height = pipe_config->pipe_src_h;
118 		x = (adjusted_mode->crtc_hdisplay - width + 1)/2;
119 		y = (adjusted_mode->crtc_vdisplay - height + 1)/2;
120 		break;
121 
122 	case DRM_MODE_SCALE_ASPECT:
123 		/* Scale but preserve the aspect ratio */
124 		{
125 			u32 scaled_width = adjusted_mode->crtc_hdisplay
126 				* pipe_config->pipe_src_h;
127 			u32 scaled_height = pipe_config->pipe_src_w
128 				* adjusted_mode->crtc_vdisplay;
129 			if (scaled_width > scaled_height) { /* pillar */
130 				width = scaled_height / pipe_config->pipe_src_h;
131 				if (width & 1)
132 					width++;
133 				x = (adjusted_mode->crtc_hdisplay - width + 1) / 2;
134 				y = 0;
135 				height = adjusted_mode->crtc_vdisplay;
136 			} else if (scaled_width < scaled_height) { /* letter */
137 				height = scaled_width / pipe_config->pipe_src_w;
138 				if (height & 1)
139 				    height++;
140 				y = (adjusted_mode->crtc_vdisplay - height + 1) / 2;
141 				x = 0;
142 				width = adjusted_mode->crtc_hdisplay;
143 			} else {
144 				x = y = 0;
145 				width = adjusted_mode->crtc_hdisplay;
146 				height = adjusted_mode->crtc_vdisplay;
147 			}
148 		}
149 		break;
150 
151 	case DRM_MODE_SCALE_FULLSCREEN:
152 		x = y = 0;
153 		width = adjusted_mode->crtc_hdisplay;
154 		height = adjusted_mode->crtc_vdisplay;
155 		break;
156 
157 	default:
158 		WARN(1, "bad panel fit mode: %d\n", fitting_mode);
159 		return;
160 	}
161 
162 done:
163 	pipe_config->pch_pfit.pos = (x << 16) | y;
164 	pipe_config->pch_pfit.size = (width << 16) | height;
165 	pipe_config->pch_pfit.enabled = pipe_config->pch_pfit.size != 0;
166 }
167 
168 static void
169 centre_horizontally(struct drm_display_mode *adjusted_mode,
170 		    int width)
171 {
172 	u32 border, sync_pos, blank_width, sync_width;
173 
174 	/* keep the hsync and hblank widths constant */
175 	sync_width = adjusted_mode->crtc_hsync_end - adjusted_mode->crtc_hsync_start;
176 	blank_width = adjusted_mode->crtc_hblank_end - adjusted_mode->crtc_hblank_start;
177 	sync_pos = (blank_width - sync_width + 1) / 2;
178 
179 	border = (adjusted_mode->crtc_hdisplay - width + 1) / 2;
180 	border += border & 1; /* make the border even */
181 
182 	adjusted_mode->crtc_hdisplay = width;
183 	adjusted_mode->crtc_hblank_start = width + border;
184 	adjusted_mode->crtc_hblank_end = adjusted_mode->crtc_hblank_start + blank_width;
185 
186 	adjusted_mode->crtc_hsync_start = adjusted_mode->crtc_hblank_start + sync_pos;
187 	adjusted_mode->crtc_hsync_end = adjusted_mode->crtc_hsync_start + sync_width;
188 }
189 
190 static void
191 centre_vertically(struct drm_display_mode *adjusted_mode,
192 		  int height)
193 {
194 	u32 border, sync_pos, blank_width, sync_width;
195 
196 	/* keep the vsync and vblank widths constant */
197 	sync_width = adjusted_mode->crtc_vsync_end - adjusted_mode->crtc_vsync_start;
198 	blank_width = adjusted_mode->crtc_vblank_end - adjusted_mode->crtc_vblank_start;
199 	sync_pos = (blank_width - sync_width + 1) / 2;
200 
201 	border = (adjusted_mode->crtc_vdisplay - height + 1) / 2;
202 
203 	adjusted_mode->crtc_vdisplay = height;
204 	adjusted_mode->crtc_vblank_start = height + border;
205 	adjusted_mode->crtc_vblank_end = adjusted_mode->crtc_vblank_start + blank_width;
206 
207 	adjusted_mode->crtc_vsync_start = adjusted_mode->crtc_vblank_start + sync_pos;
208 	adjusted_mode->crtc_vsync_end = adjusted_mode->crtc_vsync_start + sync_width;
209 }
210 
211 static inline u32 panel_fitter_scaling(u32 source, u32 target)
212 {
213 	/*
214 	 * Floating point operation is not supported. So the FACTOR
215 	 * is defined, which can avoid the floating point computation
216 	 * when calculating the panel ratio.
217 	 */
218 #define ACCURACY 12
219 #define FACTOR (1 << ACCURACY)
220 	u32 ratio = source * FACTOR / target;
221 	return (FACTOR * ratio + FACTOR/2) / FACTOR;
222 }
223 
224 static void i965_scale_aspect(struct intel_crtc_state *pipe_config,
225 			      u32 *pfit_control)
226 {
227 	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
228 	u32 scaled_width = adjusted_mode->crtc_hdisplay *
229 		pipe_config->pipe_src_h;
230 	u32 scaled_height = pipe_config->pipe_src_w *
231 		adjusted_mode->crtc_vdisplay;
232 
233 	/* 965+ is easy, it does everything in hw */
234 	if (scaled_width > scaled_height)
235 		*pfit_control |= PFIT_ENABLE |
236 			PFIT_SCALING_PILLAR;
237 	else if (scaled_width < scaled_height)
238 		*pfit_control |= PFIT_ENABLE |
239 			PFIT_SCALING_LETTER;
240 	else if (adjusted_mode->crtc_hdisplay != pipe_config->pipe_src_w)
241 		*pfit_control |= PFIT_ENABLE | PFIT_SCALING_AUTO;
242 }
243 
244 static void i9xx_scale_aspect(struct intel_crtc_state *pipe_config,
245 			      u32 *pfit_control, u32 *pfit_pgm_ratios,
246 			      u32 *border)
247 {
248 	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
249 	u32 scaled_width = adjusted_mode->crtc_hdisplay *
250 		pipe_config->pipe_src_h;
251 	u32 scaled_height = pipe_config->pipe_src_w *
252 		adjusted_mode->crtc_vdisplay;
253 	u32 bits;
254 
255 	/*
256 	 * For earlier chips we have to calculate the scaling
257 	 * ratio by hand and program it into the
258 	 * PFIT_PGM_RATIO register
259 	 */
260 	if (scaled_width > scaled_height) { /* pillar */
261 		centre_horizontally(adjusted_mode,
262 				    scaled_height /
263 				    pipe_config->pipe_src_h);
264 
265 		*border = LVDS_BORDER_ENABLE;
266 		if (pipe_config->pipe_src_h != adjusted_mode->crtc_vdisplay) {
267 			bits = panel_fitter_scaling(pipe_config->pipe_src_h,
268 						    adjusted_mode->crtc_vdisplay);
269 
270 			*pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
271 					     bits << PFIT_VERT_SCALE_SHIFT);
272 			*pfit_control |= (PFIT_ENABLE |
273 					  VERT_INTERP_BILINEAR |
274 					  HORIZ_INTERP_BILINEAR);
275 		}
276 	} else if (scaled_width < scaled_height) { /* letter */
277 		centre_vertically(adjusted_mode,
278 				  scaled_width /
279 				  pipe_config->pipe_src_w);
280 
281 		*border = LVDS_BORDER_ENABLE;
282 		if (pipe_config->pipe_src_w != adjusted_mode->crtc_hdisplay) {
283 			bits = panel_fitter_scaling(pipe_config->pipe_src_w,
284 						    adjusted_mode->crtc_hdisplay);
285 
286 			*pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
287 					     bits << PFIT_VERT_SCALE_SHIFT);
288 			*pfit_control |= (PFIT_ENABLE |
289 					  VERT_INTERP_BILINEAR |
290 					  HORIZ_INTERP_BILINEAR);
291 		}
292 	} else {
293 		/* Aspects match, Let hw scale both directions */
294 		*pfit_control |= (PFIT_ENABLE |
295 				  VERT_AUTO_SCALE | HORIZ_AUTO_SCALE |
296 				  VERT_INTERP_BILINEAR |
297 				  HORIZ_INTERP_BILINEAR);
298 	}
299 }
300 
301 void intel_gmch_panel_fitting(struct intel_crtc *intel_crtc,
302 			      struct intel_crtc_state *pipe_config,
303 			      int fitting_mode)
304 {
305 	struct drm_device *dev = intel_crtc->base.dev;
306 	u32 pfit_control = 0, pfit_pgm_ratios = 0, border = 0;
307 	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
308 
309 	/* Native modes don't need fitting */
310 	if (adjusted_mode->crtc_hdisplay == pipe_config->pipe_src_w &&
311 	    adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h)
312 		goto out;
313 
314 	switch (fitting_mode) {
315 	case DRM_MODE_SCALE_CENTER:
316 		/*
317 		 * For centered modes, we have to calculate border widths &
318 		 * heights and modify the values programmed into the CRTC.
319 		 */
320 		centre_horizontally(adjusted_mode, pipe_config->pipe_src_w);
321 		centre_vertically(adjusted_mode, pipe_config->pipe_src_h);
322 		border = LVDS_BORDER_ENABLE;
323 		break;
324 	case DRM_MODE_SCALE_ASPECT:
325 		/* Scale but preserve the aspect ratio */
326 		if (INTEL_INFO(dev)->gen >= 4)
327 			i965_scale_aspect(pipe_config, &pfit_control);
328 		else
329 			i9xx_scale_aspect(pipe_config, &pfit_control,
330 					  &pfit_pgm_ratios, &border);
331 		break;
332 	case DRM_MODE_SCALE_FULLSCREEN:
333 		/*
334 		 * Full scaling, even if it changes the aspect ratio.
335 		 * Fortunately this is all done for us in hw.
336 		 */
337 		if (pipe_config->pipe_src_h != adjusted_mode->crtc_vdisplay ||
338 		    pipe_config->pipe_src_w != adjusted_mode->crtc_hdisplay) {
339 			pfit_control |= PFIT_ENABLE;
340 			if (INTEL_INFO(dev)->gen >= 4)
341 				pfit_control |= PFIT_SCALING_AUTO;
342 			else
343 				pfit_control |= (VERT_AUTO_SCALE |
344 						 VERT_INTERP_BILINEAR |
345 						 HORIZ_AUTO_SCALE |
346 						 HORIZ_INTERP_BILINEAR);
347 		}
348 		break;
349 	default:
350 		WARN(1, "bad panel fit mode: %d\n", fitting_mode);
351 		return;
352 	}
353 
354 	/* 965+ wants fuzzy fitting */
355 	/* FIXME: handle multiple panels by failing gracefully */
356 	if (INTEL_INFO(dev)->gen >= 4)
357 		pfit_control |= ((intel_crtc->pipe << PFIT_PIPE_SHIFT) |
358 				 PFIT_FILTER_FUZZY);
359 
360 out:
361 	if ((pfit_control & PFIT_ENABLE) == 0) {
362 		pfit_control = 0;
363 		pfit_pgm_ratios = 0;
364 	}
365 
366 	/* Make sure pre-965 set dither correctly for 18bpp panels. */
367 	if (INTEL_INFO(dev)->gen < 4 && pipe_config->pipe_bpp == 18)
368 		pfit_control |= PANEL_8TO6_DITHER_ENABLE;
369 
370 	pipe_config->gmch_pfit.control = pfit_control;
371 	pipe_config->gmch_pfit.pgm_ratios = pfit_pgm_ratios;
372 	pipe_config->gmch_pfit.lvds_border_bits = border;
373 }
374 
375 enum drm_connector_status
376 intel_panel_detect(struct drm_device *dev)
377 {
378 	struct drm_i915_private *dev_priv = dev->dev_private;
379 
380 	/* Assume that the BIOS does not lie through the OpRegion... */
381 	if (!i915.panel_ignore_lid && dev_priv->opregion.lid_state) {
382 		return *dev_priv->opregion.lid_state & 0x1 ?
383 			connector_status_connected :
384 			connector_status_disconnected;
385 	}
386 
387 	switch (i915.panel_ignore_lid) {
388 	case -2:
389 		return connector_status_connected;
390 	case -1:
391 		return connector_status_disconnected;
392 	default:
393 		return connector_status_unknown;
394 	}
395 }
396 
397 /**
398  * scale - scale values from one range to another
399  *
400  * @source_val: value in range [@source_min..@source_max]
401  *
402  * Return @source_val in range [@source_min..@source_max] scaled to range
403  * [@target_min..@target_max].
404  */
405 static uint32_t scale(uint32_t source_val,
406 		      uint32_t source_min, uint32_t source_max,
407 		      uint32_t target_min, uint32_t target_max)
408 {
409 	uint64_t target_val;
410 
411 	WARN_ON(source_min > source_max);
412 	WARN_ON(target_min > target_max);
413 
414 	/* defensive */
415 	source_val = clamp(source_val, source_min, source_max);
416 
417 	/* avoid overflows */
418 	target_val = DIV_ROUND_CLOSEST_ULL((uint64_t)(source_val - source_min) *
419 			(target_max - target_min), source_max - source_min);
420 	target_val += target_min;
421 
422 	return target_val;
423 }
424 
425 /* Scale user_level in range [0..user_max] to [hw_min..hw_max]. */
426 static inline u32 scale_user_to_hw(struct intel_connector *connector,
427 				   u32 user_level, u32 user_max)
428 {
429 	struct intel_panel *panel = &connector->panel;
430 
431 	return scale(user_level, 0, user_max,
432 		     panel->backlight.min, panel->backlight.max);
433 }
434 
435 /* Scale user_level in range [0..user_max] to [0..hw_max], clamping the result
436  * to [hw_min..hw_max]. */
437 static inline u32 clamp_user_to_hw(struct intel_connector *connector,
438 				   u32 user_level, u32 user_max)
439 {
440 	struct intel_panel *panel = &connector->panel;
441 	u32 hw_level;
442 
443 	hw_level = scale(user_level, 0, user_max, 0, panel->backlight.max);
444 	hw_level = clamp(hw_level, panel->backlight.min, panel->backlight.max);
445 
446 	return hw_level;
447 }
448 
449 /* Scale hw_level in range [hw_min..hw_max] to [0..user_max]. */
450 static inline u32 scale_hw_to_user(struct intel_connector *connector,
451 				   u32 hw_level, u32 user_max)
452 {
453 	struct intel_panel *panel = &connector->panel;
454 
455 	return scale(hw_level, panel->backlight.min, panel->backlight.max,
456 		     0, user_max);
457 }
458 
459 static u32 intel_panel_compute_brightness(struct intel_connector *connector,
460 					  u32 val)
461 {
462 	struct drm_device *dev = connector->base.dev;
463 	struct drm_i915_private *dev_priv = dev->dev_private;
464 	struct intel_panel *panel = &connector->panel;
465 
466 	WARN_ON(panel->backlight.max == 0);
467 
468 	if (i915.invert_brightness < 0)
469 		return val;
470 
471 	if (i915.invert_brightness > 0 ||
472 	    dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) {
473 		return panel->backlight.max - val;
474 	}
475 
476 	return val;
477 }
478 
479 static u32 lpt_get_backlight(struct intel_connector *connector)
480 {
481 	struct drm_device *dev = connector->base.dev;
482 	struct drm_i915_private *dev_priv = dev->dev_private;
483 
484 	return I915_READ(BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
485 }
486 
487 static u32 pch_get_backlight(struct intel_connector *connector)
488 {
489 	struct drm_device *dev = connector->base.dev;
490 	struct drm_i915_private *dev_priv = dev->dev_private;
491 
492 	return I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
493 }
494 
495 static u32 i9xx_get_backlight(struct intel_connector *connector)
496 {
497 	struct drm_device *dev = connector->base.dev;
498 	struct drm_i915_private *dev_priv = dev->dev_private;
499 	struct intel_panel *panel = &connector->panel;
500 	u32 val;
501 
502 	val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
503 	if (INTEL_INFO(dev)->gen < 4)
504 		val >>= 1;
505 
506 	if (panel->backlight.combination_mode) {
507 		u8 lbpc;
508 
509 		pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
510 		val *= lbpc;
511 	}
512 
513 	return val;
514 }
515 
516 static u32 _vlv_get_backlight(struct drm_device *dev, enum i915_pipe pipe)
517 {
518 	struct drm_i915_private *dev_priv = dev->dev_private;
519 
520 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
521 		return 0;
522 
523 	return I915_READ(VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK;
524 }
525 
526 static u32 vlv_get_backlight(struct intel_connector *connector)
527 {
528 	struct drm_device *dev = connector->base.dev;
529 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
530 
531 	return _vlv_get_backlight(dev, pipe);
532 }
533 
534 static u32 bxt_get_backlight(struct intel_connector *connector)
535 {
536 	struct drm_device *dev = connector->base.dev;
537 	struct intel_panel *panel = &connector->panel;
538 	struct drm_i915_private *dev_priv = dev->dev_private;
539 
540 	return I915_READ(BXT_BLC_PWM_DUTY(panel->backlight.controller));
541 }
542 
543 static u32 pwm_get_backlight(struct intel_connector *connector)
544 {
545 	struct intel_panel *panel = &connector->panel;
546 	int duty_ns;
547 
548 	duty_ns = pwm_get_duty_cycle(panel->backlight.pwm);
549 	return DIV_ROUND_UP(duty_ns * 100, CRC_PMIC_PWM_PERIOD_NS);
550 }
551 
552 #if 0
553 static u32 intel_panel_get_backlight(struct intel_connector *connector)
554 {
555 	struct drm_device *dev = connector->base.dev;
556 	struct drm_i915_private *dev_priv = dev->dev_private;
557 	struct intel_panel *panel = &connector->panel;
558 	u32 val = 0;
559 
560 	mutex_lock(&dev_priv->backlight_lock);
561 
562 	if (panel->backlight.enabled) {
563 		val = panel->backlight.get(connector);
564 		val = intel_panel_compute_brightness(connector, val);
565 	}
566 
567 	mutex_unlock(&dev_priv->backlight_lock);
568 
569 	DRM_DEBUG_DRIVER("get backlight PWM = %d\n", val);
570 	return val;
571 }
572 #endif
573 
574 static void lpt_set_backlight(struct intel_connector *connector, u32 level)
575 {
576 	struct drm_device *dev = connector->base.dev;
577 	struct drm_i915_private *dev_priv = dev->dev_private;
578 	u32 val = I915_READ(BLC_PWM_PCH_CTL2) & ~BACKLIGHT_DUTY_CYCLE_MASK;
579 	I915_WRITE(BLC_PWM_PCH_CTL2, val | level);
580 }
581 
582 static void pch_set_backlight(struct intel_connector *connector, u32 level)
583 {
584 	struct drm_device *dev = connector->base.dev;
585 	struct drm_i915_private *dev_priv = dev->dev_private;
586 	u32 tmp;
587 
588 	tmp = I915_READ(BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
589 	I915_WRITE(BLC_PWM_CPU_CTL, tmp | level);
590 }
591 
592 static void i9xx_set_backlight(struct intel_connector *connector, u32 level)
593 {
594 	struct drm_device *dev = connector->base.dev;
595 	struct drm_i915_private *dev_priv = dev->dev_private;
596 	struct intel_panel *panel = &connector->panel;
597 	u32 tmp, mask;
598 
599 	WARN_ON(panel->backlight.max == 0);
600 
601 	if (panel->backlight.combination_mode) {
602 		u8 lbpc;
603 
604 		lbpc = level * 0xfe / panel->backlight.max + 1;
605 		level /= lbpc;
606 		pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
607 	}
608 
609 	if (IS_GEN4(dev)) {
610 		mask = BACKLIGHT_DUTY_CYCLE_MASK;
611 	} else {
612 		level <<= 1;
613 		mask = BACKLIGHT_DUTY_CYCLE_MASK_PNV;
614 	}
615 
616 	tmp = I915_READ(BLC_PWM_CTL) & ~mask;
617 	I915_WRITE(BLC_PWM_CTL, tmp | level);
618 }
619 
620 static void vlv_set_backlight(struct intel_connector *connector, u32 level)
621 {
622 	struct drm_device *dev = connector->base.dev;
623 	struct drm_i915_private *dev_priv = dev->dev_private;
624 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
625 	u32 tmp;
626 
627 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
628 		return;
629 
630 	tmp = I915_READ(VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK;
631 	I915_WRITE(VLV_BLC_PWM_CTL(pipe), tmp | level);
632 }
633 
634 static void bxt_set_backlight(struct intel_connector *connector, u32 level)
635 {
636 	struct drm_device *dev = connector->base.dev;
637 	struct drm_i915_private *dev_priv = dev->dev_private;
638 	struct intel_panel *panel = &connector->panel;
639 
640 	I915_WRITE(BXT_BLC_PWM_DUTY(panel->backlight.controller), level);
641 }
642 
643 static void pwm_set_backlight(struct intel_connector *connector, u32 level)
644 {
645 	struct intel_panel *panel = &connector->panel;
646 	int duty_ns = DIV_ROUND_UP(level * CRC_PMIC_PWM_PERIOD_NS, 100);
647 
648 	pwm_config(panel->backlight.pwm, duty_ns, CRC_PMIC_PWM_PERIOD_NS);
649 }
650 
651 static void
652 intel_panel_actually_set_backlight(struct intel_connector *connector, u32 level)
653 {
654 	struct intel_panel *panel = &connector->panel;
655 
656 	DRM_DEBUG_DRIVER("set backlight PWM = %d\n", level);
657 
658 	level = intel_panel_compute_brightness(connector, level);
659 	panel->backlight.set(connector, level);
660 }
661 
662 /* set backlight brightness to level in range [0..max], scaling wrt hw min */
663 static void intel_panel_set_backlight(struct intel_connector *connector,
664 				      u32 user_level, u32 user_max)
665 {
666 	struct drm_device *dev = connector->base.dev;
667 	struct drm_i915_private *dev_priv = dev->dev_private;
668 	struct intel_panel *panel = &connector->panel;
669 	u32 hw_level;
670 
671 	if (!panel->backlight.present)
672 		return;
673 
674 	mutex_lock(&dev_priv->backlight_lock);
675 
676 	WARN_ON(panel->backlight.max == 0);
677 
678 	hw_level = scale_user_to_hw(connector, user_level, user_max);
679 	panel->backlight.level = hw_level;
680 
681 	if (panel->backlight.enabled)
682 		intel_panel_actually_set_backlight(connector, hw_level);
683 
684 	mutex_unlock(&dev_priv->backlight_lock);
685 }
686 
687 /* set backlight brightness to level in range [0..max], assuming hw min is
688  * respected.
689  */
690 void intel_panel_set_backlight_acpi(struct intel_connector *connector,
691 				    u32 user_level, u32 user_max)
692 {
693 	struct drm_device *dev = connector->base.dev;
694 	struct drm_i915_private *dev_priv = dev->dev_private;
695 	struct intel_panel *panel = &connector->panel;
696 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
697 	u32 hw_level;
698 
699 	/*
700 	 * INVALID_PIPE may occur during driver init because
701 	 * connection_mutex isn't held across the entire backlight
702 	 * setup + modeset readout, and the BIOS can issue the
703 	 * requests at any time.
704 	 */
705 	if (!panel->backlight.present || pipe == INVALID_PIPE)
706 		return;
707 
708 	mutex_lock(&dev_priv->backlight_lock);
709 
710 	WARN_ON(panel->backlight.max == 0);
711 
712 	hw_level = clamp_user_to_hw(connector, user_level, user_max);
713 	panel->backlight.level = hw_level;
714 
715 	if (panel->backlight.device)
716 		panel->backlight.device->props.brightness =
717 			scale_hw_to_user(connector,
718 					 panel->backlight.level,
719 					 panel->backlight.device->props.max_brightness);
720 
721 	if (panel->backlight.enabled)
722 		intel_panel_actually_set_backlight(connector, hw_level);
723 
724 	mutex_unlock(&dev_priv->backlight_lock);
725 }
726 
727 static void lpt_disable_backlight(struct intel_connector *connector)
728 {
729 	struct drm_device *dev = connector->base.dev;
730 	struct drm_i915_private *dev_priv = dev->dev_private;
731 	u32 tmp;
732 
733 	intel_panel_actually_set_backlight(connector, 0);
734 
735 	/*
736 	 * Although we don't support or enable CPU PWM with LPT/SPT based
737 	 * systems, it may have been enabled prior to loading the
738 	 * driver. Disable to avoid warnings on LCPLL disable.
739 	 *
740 	 * This needs rework if we need to add support for CPU PWM on PCH split
741 	 * platforms.
742 	 */
743 	tmp = I915_READ(BLC_PWM_CPU_CTL2);
744 	if (tmp & BLM_PWM_ENABLE) {
745 		DRM_DEBUG_KMS("cpu backlight was enabled, disabling\n");
746 		I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
747 	}
748 
749 	tmp = I915_READ(BLC_PWM_PCH_CTL1);
750 	I915_WRITE(BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE);
751 }
752 
753 static void pch_disable_backlight(struct intel_connector *connector)
754 {
755 	struct drm_device *dev = connector->base.dev;
756 	struct drm_i915_private *dev_priv = dev->dev_private;
757 	u32 tmp;
758 
759 	intel_panel_actually_set_backlight(connector, 0);
760 
761 	tmp = I915_READ(BLC_PWM_CPU_CTL2);
762 	I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
763 
764 	tmp = I915_READ(BLC_PWM_PCH_CTL1);
765 	I915_WRITE(BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE);
766 }
767 
768 static void i9xx_disable_backlight(struct intel_connector *connector)
769 {
770 	intel_panel_actually_set_backlight(connector, 0);
771 }
772 
773 static void i965_disable_backlight(struct intel_connector *connector)
774 {
775 	struct drm_device *dev = connector->base.dev;
776 	struct drm_i915_private *dev_priv = dev->dev_private;
777 	u32 tmp;
778 
779 	intel_panel_actually_set_backlight(connector, 0);
780 
781 	tmp = I915_READ(BLC_PWM_CTL2);
782 	I915_WRITE(BLC_PWM_CTL2, tmp & ~BLM_PWM_ENABLE);
783 }
784 
785 static void vlv_disable_backlight(struct intel_connector *connector)
786 {
787 	struct drm_device *dev = connector->base.dev;
788 	struct drm_i915_private *dev_priv = dev->dev_private;
789 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
790 	u32 tmp;
791 
792 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
793 		return;
794 
795 	intel_panel_actually_set_backlight(connector, 0);
796 
797 	tmp = I915_READ(VLV_BLC_PWM_CTL2(pipe));
798 	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), tmp & ~BLM_PWM_ENABLE);
799 }
800 
801 static void bxt_disable_backlight(struct intel_connector *connector)
802 {
803 	struct drm_device *dev = connector->base.dev;
804 	struct drm_i915_private *dev_priv = dev->dev_private;
805 	struct intel_panel *panel = &connector->panel;
806 	u32 tmp, val;
807 
808 	intel_panel_actually_set_backlight(connector, 0);
809 
810 	tmp = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
811 	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
812 			tmp & ~BXT_BLC_PWM_ENABLE);
813 
814 	if (panel->backlight.controller == 1) {
815 		val = I915_READ(UTIL_PIN_CTL);
816 		val &= ~UTIL_PIN_ENABLE;
817 		I915_WRITE(UTIL_PIN_CTL, val);
818 	}
819 }
820 
821 static void pwm_disable_backlight(struct intel_connector *connector)
822 {
823 	struct intel_panel *panel = &connector->panel;
824 
825 	/* Disable the backlight */
826 	pwm_config(panel->backlight.pwm, 0, CRC_PMIC_PWM_PERIOD_NS);
827 	usleep_range(2000, 3000);
828 	pwm_disable(panel->backlight.pwm);
829 }
830 
831 void intel_panel_disable_backlight(struct intel_connector *connector)
832 {
833 	struct drm_device *dev = connector->base.dev;
834 	struct drm_i915_private *dev_priv = dev->dev_private;
835 	struct intel_panel *panel = &connector->panel;
836 
837 	if (!panel->backlight.present)
838 		return;
839 
840 	/*
841 	 * Do not disable backlight on the vga_switcheroo path. When switching
842 	 * away from i915, the other client may depend on i915 to handle the
843 	 * backlight. This will leave the backlight on unnecessarily when
844 	 * another client is not activated.
845 	 */
846 	if (dev->switch_power_state == DRM_SWITCH_POWER_CHANGING) {
847 		DRM_DEBUG_DRIVER("Skipping backlight disable on vga switch\n");
848 		return;
849 	}
850 
851 	mutex_lock(&dev_priv->backlight_lock);
852 
853 	if (panel->backlight.device)
854 		panel->backlight.device->props.power = FB_BLANK_POWERDOWN;
855 	panel->backlight.enabled = false;
856 	panel->backlight.disable(connector);
857 
858 	mutex_unlock(&dev_priv->backlight_lock);
859 }
860 
861 static void lpt_enable_backlight(struct intel_connector *connector)
862 {
863 	struct drm_device *dev = connector->base.dev;
864 	struct drm_i915_private *dev_priv = dev->dev_private;
865 	struct intel_panel *panel = &connector->panel;
866 	u32 pch_ctl1, pch_ctl2;
867 
868 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
869 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
870 		DRM_DEBUG_KMS("pch backlight already enabled\n");
871 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
872 		I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
873 	}
874 
875 	pch_ctl2 = panel->backlight.max << 16;
876 	I915_WRITE(BLC_PWM_PCH_CTL2, pch_ctl2);
877 
878 	pch_ctl1 = 0;
879 	if (panel->backlight.active_low_pwm)
880 		pch_ctl1 |= BLM_PCH_POLARITY;
881 
882 	/* After LPT, override is the default. */
883 	if (HAS_PCH_LPT(dev_priv))
884 		pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
885 
886 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
887 	POSTING_READ(BLC_PWM_PCH_CTL1);
888 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
889 
890 	/* This won't stick until the above enable. */
891 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
892 }
893 
894 static void pch_enable_backlight(struct intel_connector *connector)
895 {
896 	struct drm_device *dev = connector->base.dev;
897 	struct drm_i915_private *dev_priv = dev->dev_private;
898 	struct intel_panel *panel = &connector->panel;
899 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
900 	enum transcoder cpu_transcoder =
901 		intel_pipe_to_cpu_transcoder(dev_priv, pipe);
902 	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
903 
904 	cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
905 	if (cpu_ctl2 & BLM_PWM_ENABLE) {
906 		DRM_DEBUG_KMS("cpu backlight already enabled\n");
907 		cpu_ctl2 &= ~BLM_PWM_ENABLE;
908 		I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2);
909 	}
910 
911 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
912 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
913 		DRM_DEBUG_KMS("pch backlight already enabled\n");
914 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
915 		I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
916 	}
917 
918 	if (cpu_transcoder == TRANSCODER_EDP)
919 		cpu_ctl2 = BLM_TRANSCODER_EDP;
920 	else
921 		cpu_ctl2 = BLM_PIPE(cpu_transcoder);
922 	I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2);
923 	POSTING_READ(BLC_PWM_CPU_CTL2);
924 	I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2 | BLM_PWM_ENABLE);
925 
926 	/* This won't stick until the above enable. */
927 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
928 
929 	pch_ctl2 = panel->backlight.max << 16;
930 	I915_WRITE(BLC_PWM_PCH_CTL2, pch_ctl2);
931 
932 	pch_ctl1 = 0;
933 	if (panel->backlight.active_low_pwm)
934 		pch_ctl1 |= BLM_PCH_POLARITY;
935 
936 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
937 	POSTING_READ(BLC_PWM_PCH_CTL1);
938 	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
939 }
940 
941 static void i9xx_enable_backlight(struct intel_connector *connector)
942 {
943 	struct drm_device *dev = connector->base.dev;
944 	struct drm_i915_private *dev_priv = dev->dev_private;
945 	struct intel_panel *panel = &connector->panel;
946 	u32 ctl, freq;
947 
948 	ctl = I915_READ(BLC_PWM_CTL);
949 	if (ctl & BACKLIGHT_DUTY_CYCLE_MASK_PNV) {
950 		DRM_DEBUG_KMS("backlight already enabled\n");
951 		I915_WRITE(BLC_PWM_CTL, 0);
952 	}
953 
954 	freq = panel->backlight.max;
955 	if (panel->backlight.combination_mode)
956 		freq /= 0xff;
957 
958 	ctl = freq << 17;
959 	if (panel->backlight.combination_mode)
960 		ctl |= BLM_LEGACY_MODE;
961 	if (IS_PINEVIEW(dev) && panel->backlight.active_low_pwm)
962 		ctl |= BLM_POLARITY_PNV;
963 
964 	I915_WRITE(BLC_PWM_CTL, ctl);
965 	POSTING_READ(BLC_PWM_CTL);
966 
967 	/* XXX: combine this into above write? */
968 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
969 
970 	/*
971 	 * Needed to enable backlight on some 855gm models. BLC_HIST_CTL is
972 	 * 855gm only, but checking for gen2 is safe, as 855gm is the only gen2
973 	 * that has backlight.
974 	 */
975 	if (IS_GEN2(dev))
976 		I915_WRITE(BLC_HIST_CTL, BLM_HISTOGRAM_ENABLE);
977 }
978 
979 static void i965_enable_backlight(struct intel_connector *connector)
980 {
981 	struct drm_device *dev = connector->base.dev;
982 	struct drm_i915_private *dev_priv = dev->dev_private;
983 	struct intel_panel *panel = &connector->panel;
984 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
985 	u32 ctl, ctl2, freq;
986 
987 	ctl2 = I915_READ(BLC_PWM_CTL2);
988 	if (ctl2 & BLM_PWM_ENABLE) {
989 		DRM_DEBUG_KMS("backlight already enabled\n");
990 		ctl2 &= ~BLM_PWM_ENABLE;
991 		I915_WRITE(BLC_PWM_CTL2, ctl2);
992 	}
993 
994 	freq = panel->backlight.max;
995 	if (panel->backlight.combination_mode)
996 		freq /= 0xff;
997 
998 	ctl = freq << 16;
999 	I915_WRITE(BLC_PWM_CTL, ctl);
1000 
1001 	ctl2 = BLM_PIPE(pipe);
1002 	if (panel->backlight.combination_mode)
1003 		ctl2 |= BLM_COMBINATION_MODE;
1004 	if (panel->backlight.active_low_pwm)
1005 		ctl2 |= BLM_POLARITY_I965;
1006 	I915_WRITE(BLC_PWM_CTL2, ctl2);
1007 	POSTING_READ(BLC_PWM_CTL2);
1008 	I915_WRITE(BLC_PWM_CTL2, ctl2 | BLM_PWM_ENABLE);
1009 
1010 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
1011 }
1012 
1013 static void vlv_enable_backlight(struct intel_connector *connector)
1014 {
1015 	struct drm_device *dev = connector->base.dev;
1016 	struct drm_i915_private *dev_priv = dev->dev_private;
1017 	struct intel_panel *panel = &connector->panel;
1018 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
1019 	u32 ctl, ctl2;
1020 
1021 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
1022 		return;
1023 
1024 	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
1025 	if (ctl2 & BLM_PWM_ENABLE) {
1026 		DRM_DEBUG_KMS("backlight already enabled\n");
1027 		ctl2 &= ~BLM_PWM_ENABLE;
1028 		I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2);
1029 	}
1030 
1031 	ctl = panel->backlight.max << 16;
1032 	I915_WRITE(VLV_BLC_PWM_CTL(pipe), ctl);
1033 
1034 	/* XXX: combine this into above write? */
1035 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
1036 
1037 	ctl2 = 0;
1038 	if (panel->backlight.active_low_pwm)
1039 		ctl2 |= BLM_POLARITY_I965;
1040 	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2);
1041 	POSTING_READ(VLV_BLC_PWM_CTL2(pipe));
1042 	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2 | BLM_PWM_ENABLE);
1043 }
1044 
1045 static void bxt_enable_backlight(struct intel_connector *connector)
1046 {
1047 	struct drm_device *dev = connector->base.dev;
1048 	struct drm_i915_private *dev_priv = dev->dev_private;
1049 	struct intel_panel *panel = &connector->panel;
1050 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
1051 	u32 pwm_ctl, val;
1052 
1053 	/* To use 2nd set of backlight registers, utility pin has to be
1054 	 * enabled with PWM mode.
1055 	 * The field should only be changed when the utility pin is disabled
1056 	 */
1057 	if (panel->backlight.controller == 1) {
1058 		val = I915_READ(UTIL_PIN_CTL);
1059 		if (val & UTIL_PIN_ENABLE) {
1060 			DRM_DEBUG_KMS("util pin already enabled\n");
1061 			val &= ~UTIL_PIN_ENABLE;
1062 			I915_WRITE(UTIL_PIN_CTL, val);
1063 		}
1064 
1065 		val = 0;
1066 		if (panel->backlight.util_pin_active_low)
1067 			val |= UTIL_PIN_POLARITY;
1068 		I915_WRITE(UTIL_PIN_CTL, val | UTIL_PIN_PIPE(pipe) |
1069 				UTIL_PIN_MODE_PWM | UTIL_PIN_ENABLE);
1070 	}
1071 
1072 	pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
1073 	if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
1074 		DRM_DEBUG_KMS("backlight already enabled\n");
1075 		pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
1076 		I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
1077 				pwm_ctl);
1078 	}
1079 
1080 	I915_WRITE(BXT_BLC_PWM_FREQ(panel->backlight.controller),
1081 			panel->backlight.max);
1082 
1083 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
1084 
1085 	pwm_ctl = 0;
1086 	if (panel->backlight.active_low_pwm)
1087 		pwm_ctl |= BXT_BLC_PWM_POLARITY;
1088 
1089 	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller), pwm_ctl);
1090 	POSTING_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
1091 	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
1092 			pwm_ctl | BXT_BLC_PWM_ENABLE);
1093 }
1094 
1095 static void pwm_enable_backlight(struct intel_connector *connector)
1096 {
1097 	struct intel_panel *panel = &connector->panel;
1098 
1099 	pwm_enable(panel->backlight.pwm);
1100 	intel_panel_actually_set_backlight(connector, panel->backlight.level);
1101 }
1102 
1103 void intel_panel_enable_backlight(struct intel_connector *connector)
1104 {
1105 	struct drm_device *dev = connector->base.dev;
1106 	struct drm_i915_private *dev_priv = dev->dev_private;
1107 	struct intel_panel *panel = &connector->panel;
1108 	enum i915_pipe pipe = intel_get_pipe_from_connector(connector);
1109 
1110 	if (!panel->backlight.present)
1111 		return;
1112 
1113 	DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));
1114 
1115 	mutex_lock(&dev_priv->backlight_lock);
1116 
1117 	WARN_ON(panel->backlight.max == 0);
1118 
1119 	if (panel->backlight.level <= panel->backlight.min) {
1120 		panel->backlight.level = panel->backlight.max;
1121 		if (panel->backlight.device)
1122 			panel->backlight.device->props.brightness =
1123 				scale_hw_to_user(connector,
1124 						 panel->backlight.level,
1125 						 panel->backlight.device->props.max_brightness);
1126 	}
1127 
1128 	panel->backlight.enable(connector);
1129 	panel->backlight.enabled = true;
1130 	if (panel->backlight.device)
1131 		panel->backlight.device->props.power = FB_BLANK_UNBLANK;
1132 
1133 	mutex_unlock(&dev_priv->backlight_lock);
1134 }
1135 
1136 #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
1137 static int intel_backlight_device_update_status(struct backlight_device *bd)
1138 {
1139 #if 0
1140 	struct intel_connector *connector = bl_get_data(bd);
1141 	struct intel_panel *panel = &connector->panel;
1142 	struct drm_device *dev = connector->base.dev;
1143 
1144 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
1145 	DRM_DEBUG_KMS("updating intel_backlight, brightness=%d/%d\n",
1146 		      bd->props.brightness, bd->props.max_brightness);
1147 	intel_panel_set_backlight(connector, bd->props.brightness,
1148 				  bd->props.max_brightness);
1149 
1150 	/*
1151 	 * Allow flipping bl_power as a sub-state of enabled. Sadly the
1152 	 * backlight class device does not make it easy to to differentiate
1153 	 * between callbacks for brightness and bl_power, so our backlight_power
1154 	 * callback needs to take this into account.
1155 	 */
1156 	if (panel->backlight.enabled) {
1157 		if (panel->backlight.power) {
1158 			bool enable = bd->props.power == FB_BLANK_UNBLANK &&
1159 				bd->props.brightness != 0;
1160 			panel->backlight.power(connector, enable);
1161 		}
1162 	} else {
1163 		bd->props.power = FB_BLANK_POWERDOWN;
1164 	}
1165 
1166 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
1167 #endif
1168 	return 0;
1169 }
1170 
1171 static int intel_backlight_device_get_brightness(struct backlight_device *bd)
1172 {
1173 #if 0
1174 	struct intel_connector *connector = bl_get_data(bd);
1175 	struct drm_device *dev = connector->base.dev;
1176 	struct drm_i915_private *dev_priv = dev->dev_private;
1177 	u32 hw_level;
1178 	int ret;
1179 
1180 	intel_runtime_pm_get(dev_priv);
1181 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
1182 
1183 	hw_level = intel_panel_get_backlight(connector);
1184 	ret = scale_hw_to_user(connector, hw_level, bd->props.max_brightness);
1185 
1186 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
1187 	intel_runtime_pm_put(dev_priv);
1188 
1189 	return ret;
1190 #endif
1191 	return 0;
1192 }
1193 
1194 static const struct backlight_ops intel_backlight_device_ops = {
1195 	.update_status = intel_backlight_device_update_status,
1196 	.get_brightness = intel_backlight_device_get_brightness,
1197 };
1198 
1199 static int intel_backlight_device_register(struct intel_connector *connector)
1200 {
1201 	struct intel_panel *panel = &connector->panel;
1202 	struct backlight_properties props;
1203 
1204 	if (WARN_ON(panel->backlight.device))
1205 		return -ENODEV;
1206 
1207 	if (!panel->backlight.present)
1208 		return 0;
1209 
1210 	WARN_ON(panel->backlight.max == 0);
1211 
1212 	memset(&props, 0, sizeof(props));
1213 	props.type = BACKLIGHT_RAW;
1214 
1215 	/*
1216 	 * Note: Everything should work even if the backlight device max
1217 	 * presented to the userspace is arbitrarily chosen.
1218 	 */
1219 	props.max_brightness = panel->backlight.max;
1220 	props.brightness = scale_hw_to_user(connector,
1221 					    panel->backlight.level,
1222 					    props.max_brightness);
1223 
1224 	if (panel->backlight.enabled)
1225 		props.power = FB_BLANK_UNBLANK;
1226 	else
1227 		props.power = FB_BLANK_POWERDOWN;
1228 
1229 	/*
1230 	 * Note: using the same name independent of the connector prevents
1231 	 * registration of multiple backlight devices in the driver.
1232 	 */
1233 #if 0
1234 	panel->backlight.device =
1235 		backlight_device_register("intel_backlight",
1236 					  connector->base.kdev,
1237 					  connector,
1238 					  &intel_backlight_device_ops, &props);
1239 
1240 	if (IS_ERR(panel->backlight.device)) {
1241 		DRM_ERROR("Failed to register backlight: %ld\n",
1242 			  PTR_ERR(panel->backlight.device));
1243 		panel->backlight.device = NULL;
1244 		return -ENODEV;
1245 	}
1246 
1247 	DRM_DEBUG_KMS("Connector %s backlight sysfs interface registered\n",
1248 		      connector->base.name);
1249 #endif
1250 
1251 	return 0;
1252 }
1253 
1254 static void intel_backlight_device_unregister(struct intel_connector *connector)
1255 {
1256 #if 0
1257 	struct intel_panel *panel = &connector->panel;
1258 
1259 	if (panel->backlight.device) {
1260 		backlight_device_unregister(panel->backlight.device);
1261 		panel->backlight.device = NULL;
1262 	}
1263 #endif
1264 }
1265 #else /* CONFIG_BACKLIGHT_CLASS_DEVICE */
1266 static int intel_backlight_device_register(struct intel_connector *connector)
1267 {
1268 	return 0;
1269 }
1270 static void intel_backlight_device_unregister(struct intel_connector *connector)
1271 {
1272 }
1273 #endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */
1274 
1275 /*
1276  * SPT: This value represents the period of the PWM stream in clock periods
1277  * multiplied by 16 (default increment) or 128 (alternate increment selected in
1278  * SCHICKEN_1 bit 0). PWM clock is 24 MHz.
1279  */
1280 static u32 spt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1281 {
1282 	struct drm_device *dev = connector->base.dev;
1283 	struct drm_i915_private *dev_priv = dev->dev_private;
1284 	u32 mul, clock;
1285 
1286 	if (I915_READ(SOUTH_CHICKEN1) & SPT_PWM_GRANULARITY)
1287 		mul = 128;
1288 	else
1289 		mul = 16;
1290 
1291 	clock = MHz(24);
1292 
1293 	return clock / (pwm_freq_hz * mul);
1294 }
1295 
1296 /*
1297  * LPT: This value represents the period of the PWM stream in clock periods
1298  * multiplied by 128 (default increment) or 16 (alternate increment, selected in
1299  * LPT SOUTH_CHICKEN2 register bit 5).
1300  */
1301 static u32 lpt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1302 {
1303 	struct drm_device *dev = connector->base.dev;
1304 	struct drm_i915_private *dev_priv = dev->dev_private;
1305 	u32 mul, clock;
1306 
1307 	if (I915_READ(SOUTH_CHICKEN2) & LPT_PWM_GRANULARITY)
1308 		mul = 16;
1309 	else
1310 		mul = 128;
1311 
1312 	if (dev_priv->pch_id == INTEL_PCH_LPT_DEVICE_ID_TYPE)
1313 		clock = MHz(135); /* LPT:H */
1314 	else
1315 		clock = MHz(24); /* LPT:LP */
1316 
1317 	return clock / (pwm_freq_hz * mul);
1318 }
1319 
1320 /*
1321  * ILK/SNB/IVB: This value represents the period of the PWM stream in PCH
1322  * display raw clocks multiplied by 128.
1323  */
1324 static u32 pch_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1325 {
1326 	struct drm_device *dev = connector->base.dev;
1327 	int clock = MHz(intel_pch_rawclk(dev));
1328 
1329 	return clock / (pwm_freq_hz * 128);
1330 }
1331 
1332 /*
1333  * Gen2: This field determines the number of time base events (display core
1334  * clock frequency/32) in total for a complete cycle of modulated backlight
1335  * control.
1336  *
1337  * Gen3: A time base event equals the display core clock ([DevPNV] HRAW clock)
1338  * divided by 32.
1339  */
1340 static u32 i9xx_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1341 {
1342 	struct drm_device *dev = connector->base.dev;
1343 	struct drm_i915_private *dev_priv = dev->dev_private;
1344 	int clock;
1345 
1346 	if (IS_PINEVIEW(dev))
1347 		clock = intel_hrawclk(dev);
1348 	else
1349 		clock = 1000 * dev_priv->display.get_display_clock_speed(dev);
1350 
1351 	return clock / (pwm_freq_hz * 32);
1352 }
1353 
1354 /*
1355  * Gen4: This value represents the period of the PWM stream in display core
1356  * clocks multiplied by 128.
1357  */
1358 static u32 i965_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1359 {
1360 	struct drm_device *dev = connector->base.dev;
1361 	struct drm_i915_private *dev_priv = dev->dev_private;
1362 	int clock = 1000 * dev_priv->display.get_display_clock_speed(dev);
1363 
1364 	return clock / (pwm_freq_hz * 128);
1365 }
1366 
1367 /*
1368  * VLV: This value represents the period of the PWM stream in display core
1369  * clocks ([DevCTG] 200MHz HRAW clocks) multiplied by 128 or 25MHz S0IX clocks
1370  * multiplied by 16. CHV uses a 19.2MHz S0IX clock.
1371  */
1372 static u32 vlv_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1373 {
1374 	struct drm_device *dev = connector->base.dev;
1375 	struct drm_i915_private *dev_priv = dev->dev_private;
1376 	int clock;
1377 
1378 	if ((I915_READ(CBR1_VLV) & CBR_PWM_CLOCK_MUX_SELECT) == 0) {
1379 		if (IS_CHERRYVIEW(dev))
1380 			return KHz(19200) / (pwm_freq_hz * 16);
1381 		else
1382 			return MHz(25) / (pwm_freq_hz * 16);
1383 	} else {
1384 		clock = intel_hrawclk(dev);
1385 		return MHz(clock) / (pwm_freq_hz * 128);
1386 	}
1387 }
1388 
1389 static u32 get_backlight_max_vbt(struct intel_connector *connector)
1390 {
1391 	struct drm_device *dev = connector->base.dev;
1392 	struct drm_i915_private *dev_priv = dev->dev_private;
1393 	struct intel_panel *panel = &connector->panel;
1394 	u16 pwm_freq_hz = dev_priv->vbt.backlight.pwm_freq_hz;
1395 	u32 pwm;
1396 
1397 	if (!pwm_freq_hz) {
1398 		DRM_DEBUG_KMS("backlight frequency not specified in VBT\n");
1399 		return 0;
1400 	}
1401 
1402 	if (!panel->backlight.hz_to_pwm) {
1403 		DRM_DEBUG_KMS("backlight frequency setting from VBT currently not supported on this platform\n");
1404 		return 0;
1405 	}
1406 
1407 	pwm = panel->backlight.hz_to_pwm(connector, pwm_freq_hz);
1408 	if (!pwm) {
1409 		DRM_DEBUG_KMS("backlight frequency conversion failed\n");
1410 		return 0;
1411 	}
1412 
1413 	DRM_DEBUG_KMS("backlight frequency %u Hz from VBT\n", pwm_freq_hz);
1414 
1415 	return pwm;
1416 }
1417 
1418 /*
1419  * Note: The setup hooks can't assume pipe is set!
1420  */
1421 static u32 get_backlight_min_vbt(struct intel_connector *connector)
1422 {
1423 	struct drm_device *dev = connector->base.dev;
1424 	struct drm_i915_private *dev_priv = dev->dev_private;
1425 	struct intel_panel *panel = &connector->panel;
1426 	int min;
1427 
1428 	WARN_ON(panel->backlight.max == 0);
1429 
1430 	/*
1431 	 * XXX: If the vbt value is 255, it makes min equal to max, which leads
1432 	 * to problems. There are such machines out there. Either our
1433 	 * interpretation is wrong or the vbt has bogus data. Or both. Safeguard
1434 	 * against this by letting the minimum be at most (arbitrarily chosen)
1435 	 * 25% of the max.
1436 	 */
1437 	min = clamp_t(int, dev_priv->vbt.backlight.min_brightness, 0, 64);
1438 	if (min != dev_priv->vbt.backlight.min_brightness) {
1439 		DRM_DEBUG_KMS("clamping VBT min backlight %d/255 to %d/255\n",
1440 			      dev_priv->vbt.backlight.min_brightness, min);
1441 	}
1442 
1443 	/* vbt value is a coefficient in range [0..255] */
1444 	return scale(min, 0, 255, 0, panel->backlight.max);
1445 }
1446 
1447 static int lpt_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1448 {
1449 	struct drm_device *dev = connector->base.dev;
1450 	struct drm_i915_private *dev_priv = dev->dev_private;
1451 	struct intel_panel *panel = &connector->panel;
1452 	u32 pch_ctl1, pch_ctl2, val;
1453 
1454 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
1455 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1456 
1457 	pch_ctl2 = I915_READ(BLC_PWM_PCH_CTL2);
1458 	panel->backlight.max = pch_ctl2 >> 16;
1459 
1460 	if (!panel->backlight.max)
1461 		panel->backlight.max = get_backlight_max_vbt(connector);
1462 
1463 	if (!panel->backlight.max)
1464 		return -ENODEV;
1465 
1466 	panel->backlight.min = get_backlight_min_vbt(connector);
1467 
1468 	val = lpt_get_backlight(connector);
1469 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1470 
1471 	panel->backlight.enabled = (pch_ctl1 & BLM_PCH_PWM_ENABLE) &&
1472 		panel->backlight.level != 0;
1473 
1474 	return 0;
1475 }
1476 
1477 static int pch_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1478 {
1479 	struct drm_device *dev = connector->base.dev;
1480 	struct drm_i915_private *dev_priv = dev->dev_private;
1481 	struct intel_panel *panel = &connector->panel;
1482 	u32 cpu_ctl2, pch_ctl1, pch_ctl2, val;
1483 
1484 	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
1485 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1486 
1487 	pch_ctl2 = I915_READ(BLC_PWM_PCH_CTL2);
1488 	panel->backlight.max = pch_ctl2 >> 16;
1489 
1490 	if (!panel->backlight.max)
1491 		panel->backlight.max = get_backlight_max_vbt(connector);
1492 
1493 	if (!panel->backlight.max)
1494 		return -ENODEV;
1495 
1496 	panel->backlight.min = get_backlight_min_vbt(connector);
1497 
1498 	val = pch_get_backlight(connector);
1499 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1500 
1501 	cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
1502 	panel->backlight.enabled = (cpu_ctl2 & BLM_PWM_ENABLE) &&
1503 		(pch_ctl1 & BLM_PCH_PWM_ENABLE) && panel->backlight.level != 0;
1504 
1505 	return 0;
1506 }
1507 
1508 static int i9xx_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1509 {
1510 	struct drm_device *dev = connector->base.dev;
1511 	struct drm_i915_private *dev_priv = dev->dev_private;
1512 	struct intel_panel *panel = &connector->panel;
1513 	u32 ctl, val;
1514 
1515 	ctl = I915_READ(BLC_PWM_CTL);
1516 
1517 	if (IS_GEN2(dev) || IS_I915GM(dev) || IS_I945GM(dev))
1518 		panel->backlight.combination_mode = ctl & BLM_LEGACY_MODE;
1519 
1520 	if (IS_PINEVIEW(dev))
1521 		panel->backlight.active_low_pwm = ctl & BLM_POLARITY_PNV;
1522 
1523 	panel->backlight.max = ctl >> 17;
1524 
1525 	if (!panel->backlight.max) {
1526 		panel->backlight.max = get_backlight_max_vbt(connector);
1527 		panel->backlight.max >>= 1;
1528 	}
1529 
1530 	if (!panel->backlight.max)
1531 		return -ENODEV;
1532 
1533 	if (panel->backlight.combination_mode)
1534 		panel->backlight.max *= 0xff;
1535 
1536 	panel->backlight.min = get_backlight_min_vbt(connector);
1537 
1538 	val = i9xx_get_backlight(connector);
1539 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1540 
1541 	panel->backlight.enabled = panel->backlight.level != 0;
1542 
1543 	return 0;
1544 }
1545 
1546 static int i965_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1547 {
1548 	struct drm_device *dev = connector->base.dev;
1549 	struct drm_i915_private *dev_priv = dev->dev_private;
1550 	struct intel_panel *panel = &connector->panel;
1551 	u32 ctl, ctl2, val;
1552 
1553 	ctl2 = I915_READ(BLC_PWM_CTL2);
1554 	panel->backlight.combination_mode = ctl2 & BLM_COMBINATION_MODE;
1555 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1556 
1557 	ctl = I915_READ(BLC_PWM_CTL);
1558 	panel->backlight.max = ctl >> 16;
1559 
1560 	if (!panel->backlight.max)
1561 		panel->backlight.max = get_backlight_max_vbt(connector);
1562 
1563 	if (!panel->backlight.max)
1564 		return -ENODEV;
1565 
1566 	if (panel->backlight.combination_mode)
1567 		panel->backlight.max *= 0xff;
1568 
1569 	panel->backlight.min = get_backlight_min_vbt(connector);
1570 
1571 	val = i9xx_get_backlight(connector);
1572 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1573 
1574 	panel->backlight.enabled = (ctl2 & BLM_PWM_ENABLE) &&
1575 		panel->backlight.level != 0;
1576 
1577 	return 0;
1578 }
1579 
1580 static int vlv_setup_backlight(struct intel_connector *connector, enum i915_pipe pipe)
1581 {
1582 	struct drm_device *dev = connector->base.dev;
1583 	struct drm_i915_private *dev_priv = dev->dev_private;
1584 	struct intel_panel *panel = &connector->panel;
1585 	u32 ctl, ctl2, val;
1586 
1587 	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
1588 		return -ENODEV;
1589 
1590 	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
1591 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1592 
1593 	ctl = I915_READ(VLV_BLC_PWM_CTL(pipe));
1594 	panel->backlight.max = ctl >> 16;
1595 
1596 	if (!panel->backlight.max)
1597 		panel->backlight.max = get_backlight_max_vbt(connector);
1598 
1599 	if (!panel->backlight.max)
1600 		return -ENODEV;
1601 
1602 	panel->backlight.min = get_backlight_min_vbt(connector);
1603 
1604 	val = _vlv_get_backlight(dev, pipe);
1605 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1606 
1607 	panel->backlight.enabled = (ctl2 & BLM_PWM_ENABLE) &&
1608 		panel->backlight.level != 0;
1609 
1610 	return 0;
1611 }
1612 
1613 #ifdef __DragonFly__
1614 /*
1615  * Read max backlight level
1616  */
1617 static int
1618 sysctl_backlight_max(SYSCTL_HANDLER_ARGS)
1619 {
1620 	int err, val;
1621 	struct intel_connector *connector = arg1;
1622 	struct drm_device *dev = connector->base.dev;
1623 	struct drm_i915_private *dev_priv = dev->dev_private;
1624 	struct intel_panel *panel = &connector->panel;
1625 
1626 	mutex_lock(&dev_priv->backlight_lock);
1627 	val = panel->backlight.max;
1628 	mutex_unlock(&dev_priv->backlight_lock);
1629 
1630 	err = sysctl_handle_int(oidp, &val, 0, req);
1631 	return(err);
1632 }
1633 
1634 /*
1635  * Read/write backlight level
1636  */
1637 static int
1638 sysctl_backlight_handler(SYSCTL_HANDLER_ARGS)
1639 {
1640 	struct intel_connector *connector = arg1;
1641 	struct drm_device *dev = connector->base.dev;
1642 	struct drm_i915_private *dev_priv = dev->dev_private;
1643 	struct intel_panel *panel = &connector->panel;
1644 	int err, val;
1645 	u32 user_level, max_brightness;
1646 
1647 	mutex_lock(&dev_priv->backlight_lock);
1648 	max_brightness = panel->backlight.max;
1649 	user_level = scale_hw_to_user(connector, panel->backlight.level,
1650 	    max_brightness);
1651 	mutex_unlock(&dev_priv->backlight_lock);
1652 
1653 	val = user_level;
1654 	err = sysctl_handle_int(oidp, &val, 0, req);
1655 	if (err != 0 || req->newptr == NULL) {
1656 		return(err);
1657 	}
1658 
1659 	if (val != user_level && val >= 0 && val <= max_brightness) {
1660 		drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
1661 		intel_panel_set_backlight(arg1, val, max_brightness);
1662 		drm_modeset_unlock(&dev->mode_config.connection_mutex);
1663 	}
1664 
1665 	return(err);
1666 }
1667 #endif /* __DragonFly__ */
1668 
1669 static int
1670 bxt_setup_backlight(struct intel_connector *connector, enum i915_pipe unused)
1671 {
1672 	struct drm_device *dev = connector->base.dev;
1673 	struct drm_i915_private *dev_priv = dev->dev_private;
1674 	struct intel_panel *panel = &connector->panel;
1675 	u32 pwm_ctl, val;
1676 
1677 	/*
1678 	 * For BXT hard coding the Backlight controller to 0.
1679 	 * TODO : Read the controller value from VBT and generalize
1680 	 */
1681 	panel->backlight.controller = 0;
1682 
1683 	pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
1684 
1685 	/* Keeping the check if controller 1 is to be programmed.
1686 	 * This will come into affect once the VBT parsing
1687 	 * is fixed for controller selection, and controller 1 is used
1688 	 * for a prticular display configuration.
1689 	 */
1690 	if (panel->backlight.controller == 1) {
1691 		val = I915_READ(UTIL_PIN_CTL);
1692 		panel->backlight.util_pin_active_low =
1693 					val & UTIL_PIN_POLARITY;
1694 	}
1695 
1696 	panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
1697 	panel->backlight.max =
1698 		I915_READ(BXT_BLC_PWM_FREQ(panel->backlight.controller));
1699 
1700 	if (!panel->backlight.max)
1701 		panel->backlight.max = get_backlight_max_vbt(connector);
1702 
1703 	if (!panel->backlight.max)
1704 		return -ENODEV;
1705 
1706 	val = bxt_get_backlight(connector);
1707 	panel->backlight.level = intel_panel_compute_brightness(connector, val);
1708 
1709 	panel->backlight.enabled = (pwm_ctl & BXT_BLC_PWM_ENABLE) &&
1710 		panel->backlight.level != 0;
1711 
1712 	return 0;
1713 }
1714 
1715 static int pwm_setup_backlight(struct intel_connector *connector,
1716 			       enum i915_pipe pipe)
1717 {
1718 	struct drm_device *dev = connector->base.dev;
1719 	struct intel_panel *panel = &connector->panel;
1720 	int retval;
1721 
1722 	/* Get the PWM chip for backlight control */
1723 	panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight");
1724 	if (IS_ERR(panel->backlight.pwm)) {
1725 		DRM_ERROR("Failed to own the pwm chip\n");
1726 		panel->backlight.pwm = NULL;
1727 		return -ENODEV;
1728 	}
1729 
1730 	retval = pwm_config(panel->backlight.pwm, CRC_PMIC_PWM_PERIOD_NS,
1731 			    CRC_PMIC_PWM_PERIOD_NS);
1732 	if (retval < 0) {
1733 		DRM_ERROR("Failed to configure the pwm chip\n");
1734 		pwm_put(panel->backlight.pwm);
1735 		panel->backlight.pwm = NULL;
1736 		return retval;
1737 	}
1738 
1739 	panel->backlight.min = 0; /* 0% */
1740 	panel->backlight.max = 100; /* 100% */
1741 	panel->backlight.level = DIV_ROUND_UP(
1742 				 pwm_get_duty_cycle(panel->backlight.pwm) * 100,
1743 				 CRC_PMIC_PWM_PERIOD_NS);
1744 	panel->backlight.enabled = panel->backlight.level != 0;
1745 
1746 	return 0;
1747 }
1748 
1749 int intel_panel_setup_backlight(struct drm_connector *connector, enum i915_pipe pipe)
1750 {
1751 	struct drm_device *dev = connector->dev;
1752 	struct drm_i915_private *dev_priv = dev->dev_private;
1753 	struct intel_connector *intel_connector = to_intel_connector(connector);
1754 	struct intel_panel *panel = &intel_connector->panel;
1755 	int ret;
1756 
1757 	if (!dev_priv->vbt.backlight.present) {
1758 		if (dev_priv->quirks & QUIRK_BACKLIGHT_PRESENT) {
1759 			DRM_DEBUG_KMS("no backlight present per VBT, but present per quirk\n");
1760 		} else {
1761 			DRM_DEBUG_KMS("no backlight present per VBT\n");
1762 			return 0;
1763 		}
1764 	}
1765 
1766 	/* ensure intel_panel has been initialized first */
1767 	if (WARN_ON(!panel->backlight.setup))
1768 		return -ENODEV;
1769 
1770 	/* set level and max in panel struct */
1771 	mutex_lock(&dev_priv->backlight_lock);
1772 	ret = panel->backlight.setup(intel_connector, pipe);
1773 	mutex_unlock(&dev_priv->backlight_lock);
1774 
1775 	if (ret) {
1776 		DRM_DEBUG_KMS("failed to setup backlight for connector %s\n",
1777 			      connector->name);
1778 		return ret;
1779 	}
1780 
1781 	panel->backlight.present = true;
1782 
1783 #ifdef __DragonFly__
1784 	SYSCTL_ADD_PROC(&connector->dev->sysctl->ctx, &sysctl__hw_children,
1785 			OID_AUTO, "backlight_max",
1786 			CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_ANYBODY,
1787 			connector, sizeof(int),
1788 			sysctl_backlight_max,
1789 			"I", "Max backlight level");
1790 	SYSCTL_ADD_PROC(&connector->dev->sysctl->ctx, &sysctl__hw_children,
1791 			OID_AUTO, "backlight_level",
1792 			CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_ANYBODY,
1793 			connector, sizeof(int),
1794 			sysctl_backlight_handler,
1795 			"I", "Backlight level");
1796 #endif
1797 
1798 	DRM_DEBUG_KMS("Connector %s backlight initialized, %s, brightness %u/%u\n",
1799 		      connector->name,
1800 		      panel->backlight.enabled ? "enabled" : "disabled",
1801 		      panel->backlight.level, panel->backlight.max);
1802 
1803 	return 0;
1804 }
1805 
1806 void intel_panel_destroy_backlight(struct drm_connector *connector)
1807 {
1808 	struct intel_connector *intel_connector = to_intel_connector(connector);
1809 	struct intel_panel *panel = &intel_connector->panel;
1810 
1811 	/* dispose of the pwm */
1812 	if (panel->backlight.pwm)
1813 		pwm_put(panel->backlight.pwm);
1814 
1815 	panel->backlight.present = false;
1816 }
1817 
1818 /* Set up chip specific backlight functions */
1819 static void
1820 intel_panel_init_backlight_funcs(struct intel_panel *panel)
1821 {
1822 	struct intel_connector *intel_connector =
1823 		container_of(panel, struct intel_connector, panel);
1824 	struct drm_device *dev = intel_connector->base.dev;
1825 	struct drm_i915_private *dev_priv = dev->dev_private;
1826 
1827 	if (IS_BROXTON(dev)) {
1828 		panel->backlight.setup = bxt_setup_backlight;
1829 		panel->backlight.enable = bxt_enable_backlight;
1830 		panel->backlight.disable = bxt_disable_backlight;
1831 		panel->backlight.set = bxt_set_backlight;
1832 		panel->backlight.get = bxt_get_backlight;
1833 	} else if (HAS_PCH_LPT(dev) || HAS_PCH_SPT(dev)) {
1834 		panel->backlight.setup = lpt_setup_backlight;
1835 		panel->backlight.enable = lpt_enable_backlight;
1836 		panel->backlight.disable = lpt_disable_backlight;
1837 		panel->backlight.set = lpt_set_backlight;
1838 		panel->backlight.get = lpt_get_backlight;
1839 		if (HAS_PCH_LPT(dev))
1840 			panel->backlight.hz_to_pwm = lpt_hz_to_pwm;
1841 		else
1842 			panel->backlight.hz_to_pwm = spt_hz_to_pwm;
1843 	} else if (HAS_PCH_SPLIT(dev)) {
1844 		panel->backlight.setup = pch_setup_backlight;
1845 		panel->backlight.enable = pch_enable_backlight;
1846 		panel->backlight.disable = pch_disable_backlight;
1847 		panel->backlight.set = pch_set_backlight;
1848 		panel->backlight.get = pch_get_backlight;
1849 		panel->backlight.hz_to_pwm = pch_hz_to_pwm;
1850 	} else if (IS_VALLEYVIEW(dev)) {
1851 		if (dev_priv->vbt.has_mipi) {
1852 			panel->backlight.setup = pwm_setup_backlight;
1853 			panel->backlight.enable = pwm_enable_backlight;
1854 			panel->backlight.disable = pwm_disable_backlight;
1855 			panel->backlight.set = pwm_set_backlight;
1856 			panel->backlight.get = pwm_get_backlight;
1857 		} else {
1858 			panel->backlight.setup = vlv_setup_backlight;
1859 			panel->backlight.enable = vlv_enable_backlight;
1860 			panel->backlight.disable = vlv_disable_backlight;
1861 			panel->backlight.set = vlv_set_backlight;
1862 			panel->backlight.get = vlv_get_backlight;
1863 			panel->backlight.hz_to_pwm = vlv_hz_to_pwm;
1864 		}
1865 	} else if (IS_GEN4(dev)) {
1866 		panel->backlight.setup = i965_setup_backlight;
1867 		panel->backlight.enable = i965_enable_backlight;
1868 		panel->backlight.disable = i965_disable_backlight;
1869 		panel->backlight.set = i9xx_set_backlight;
1870 		panel->backlight.get = i9xx_get_backlight;
1871 		panel->backlight.hz_to_pwm = i965_hz_to_pwm;
1872 	} else {
1873 		panel->backlight.setup = i9xx_setup_backlight;
1874 		panel->backlight.enable = i9xx_enable_backlight;
1875 		panel->backlight.disable = i9xx_disable_backlight;
1876 		panel->backlight.set = i9xx_set_backlight;
1877 		panel->backlight.get = i9xx_get_backlight;
1878 		panel->backlight.hz_to_pwm = i9xx_hz_to_pwm;
1879 	}
1880 }
1881 
1882 int intel_panel_init(struct intel_panel *panel,
1883 		     struct drm_display_mode *fixed_mode,
1884 		     struct drm_display_mode *downclock_mode)
1885 {
1886 	intel_panel_init_backlight_funcs(panel);
1887 
1888 	panel->fixed_mode = fixed_mode;
1889 	panel->downclock_mode = downclock_mode;
1890 
1891 	return 0;
1892 }
1893 
1894 void intel_panel_fini(struct intel_panel *panel)
1895 {
1896 	struct intel_connector *intel_connector =
1897 		container_of(panel, struct intel_connector, panel);
1898 
1899 	if (panel->fixed_mode)
1900 		drm_mode_destroy(intel_connector->base.dev, panel->fixed_mode);
1901 
1902 	if (panel->downclock_mode)
1903 		drm_mode_destroy(intel_connector->base.dev,
1904 				panel->downclock_mode);
1905 }
1906 
1907 void intel_backlight_register(struct drm_device *dev)
1908 {
1909 	struct intel_connector *connector;
1910 
1911 	list_for_each_entry(connector, &dev->mode_config.connector_list, base.head)
1912 		intel_backlight_device_register(connector);
1913 }
1914 
1915 void intel_backlight_unregister(struct drm_device *dev)
1916 {
1917 	struct intel_connector *connector;
1918 
1919 	list_for_each_entry(connector, &dev->mode_config.connector_list, base.head)
1920 		intel_backlight_device_unregister(connector);
1921 }
1922